A number of circumstances may make it desirable to introduce selected compounds in vapor form into the air which we breathe. One of such circumstances is the desire to associate a pleasnt odor with a commerical establishment. A second circumstance is a desire to induce a prospective customer to purchase a specific perfume. A third circumstance is to mask an unpleasant odor. The perception of an unpleasant odor may also be masked by introducing into the air compounds which deaden odor-sensing receptors in the olfactory system.
With regard to treating the air when unpleasant aromas are present, it has previously been the practice to attempt to remove the unpleasant aroma. This is an expensive proposition, particularly, for instance, at the entrance to a store. Consequently, the overcoming of unpleasant aromas by the introduction of more pleasant aromas has been the more general practice. Conventionally, in such cases, pleasant aromas are introduced in aerosol form. However, aerosol droplets are relatively large, as compared to individual molecules, so that this method of dispensing the desired material is relatively expensive. A less expensive, but equally effective means, is therefore to be desired.
A further problem which arises in connection with dispensing of odors is control over the dosage. Where there are strong draughts present, or in relatively open spaces, the quantity to be dispensed is, of necessity, larger. Therefore, provision for controlling the rate of introduction of the essence or aromatic material into the air is desirable. Such control is afforded by the present invention.